Flail mower adjustment

[leonz]

Hello Ricn,

If possible please ask them to provide you with full written information about the three control valves as somebody wearing orange is blowing smoke here.

There is the possibility that the common relief valve pressure for all three valves is set to low BUT they could should have told you that up front when all this started.


OK,

1. so you have one pair of remotes for the differential cylinder/slide cylinder

2. the second pair of remotes is for the top and tilt circuit

Where is the third remote in all this? IF you have 3 separate pairs of remotes with a total of 6 steel hydraulic lines plus
the hydraulic circuit for the lower link arms which is usually the outer hydraulic valve handle on the console making a total of four hydraulic circuits.


The lower link arms hydraulic circuit was supplied with the mule when you bought it and is fed from the oil sump of the mule.

I just hate it when a simple fix like checking the common relief valve pressure requires them to remove your mule from the property--not needed.........

If they did not set the relief valve spring pressure high enough its entirely possible that the weight of the mower is forcing the relief valve cartridge spool open and draining oil back into the tank.

If they have to remove the seat and all the extraneous mounting plates to access the steel lines and the control valve spools and the common relief valve I could see them taking it but they should have told you what they were going to do to begin with rather than just saying we want it, we want to take a look at it, which tells me they don't know what is going on with it period.

I just want you to have a mule that works. Please PM me when you know more as it does not sound like its going to be a simple fix as you would have trouble with the entire hydraulic system if the relief valve was set to low.

Its entirely possible that a piece of dirt or metal shavings is stuck in the control valve which would affect the circuit and allow it to bleed back to the sump.

 

[Ricn]

Maybe can explain better, not real smart about hydraulics. When wanting rear remotes, TBN guys suggested getting all three because, it is cheaper now than later so, I went to my dealer, the third one around here, and who was the only dealer who seemed to know about adding them to my L2501. They ordered the factory parts kits consisting of valves, hoses, fittings, and two cylinders etc. then got my tractor to install everything. When retuning the tractor it now has three sets or, six quick disconnects all mounted rather nicely behind the seat and just to the right. Also has three new levers in the slot provided right side of the seat. Two sets of remotes (four hoses) were hose fitted down to the two cylinders for T and T with the third set capped and where I plugged in the mower cylinder hoses that, after some issue finding quick disconnects that fit Kubota's factory kit fittings because, my mowers fittings were different. Keep in mind were dealing with AMERICAN,CHINESE AND JAPANESE fittings! that are all different for some reason...When having bleed-off issues I went to the dealer who said, the valve or valves maybe, were set to low but he also was sort of pissy about it telling me its common but I persisted because, mine bleeds off in about 10 min or less and is a real pain when lifting or lowering as much as I need to. He then said they would pick it up and it look over so, I am waiting for the truck. To address your second to last paragraph: my three point works fine, no bleed off, as does the top cylinder, no bleed off there or, the mower cylinder either, only the tilt cylinder bleeds down...With Warrantee in the mix here for both my tractor and the remotes, sort of have to let the dealer try and do something first..
Thanks TBN!

Ricn

 

[aczlan]

What he saying is to switch the hoses between the valve that you currently use for the top link and the valve you currently use for the side links to see if the problem follows the cylinder or the valve.

Aaron Z

 

[Ricn]

I see now. Yep, I should have thought of that: the Dealer has my tractor now so will have wait. Tnx TBN!

Ricn

 

[ovrszd]

To reinforce my claim that hydraulics simply sometimes leak, here's a pic of a new JD tractor and new 20ft JD brush cutter. We are looking at $100K of new equipment here. Notice anything?

 

[Fallon]

I've never heard of this "internal valve adjustment" that you refer to.

I want to call "BS" but will wait for the hydraulic experts to chime in....... :confused3:

I 2nd the BS call. There is no internal adjustment I know of. Also a valve should hold a full 2,500psi without leaking significantly (all hydraulics leak, but just very slowly). It doesn't matter what is at the other end either the valve leaks a lot or it doesn't.

The loader on my old L3200 & new L4060 don't move appreciably in a week. The TnT & good Butcher valves from FitRite on the L3200 would leak down over several days.

Personally I don't think anything worse than an inch an hour or 2 is acceptable. I have a hunch the rear valves on my L4060 might not pass that threshold when my TnT cylinders get here. The dealer provided me with the Kubota leakdown spec when I was dealing with the crap cylinders they were selling (since returned). I'll be measuring cylinder leakdown connected & unconnected then comparing it to the Kubota spec. I think the spec was a few tablespoons an hour or something.

Check valves are just a bandaid for bad valves. I won't use them as they break float, which is super useful

 

[Ricn]

OVRSZD - So I see rear implements with one side lower? Lots going on in the photo. Nice tractor BTW - Fallon- if adjustment is BS then my dealer is not very knowledgeable. Are you saying then the valve itself is defective? and the Kubota cylinders are crap to begin with? What do you mean by break float? getting in over my head with all this - maybe.

Ricn

 

[ovrszd]

OVRSZD - So I see rear implements with one side lower? Lots going on in the photo. Nice tractor BTW - Fallon- if adjustment is BS then my dealer is not very knowledgeable. Are you saying then the valve itself is defective? and the Kubota cylinders are crap to begin with? What do you mean by break float? getting in over my head with all this - maybe.

Ricn

The operator didn't park the tractor with one wing partially folded. The rear remote that controls the wing fold is leaking off. And that's on a $75K new tractor. See it often.

 

[Ricn]

So how long does it take to leak down and are you planning some sort of fix?

Ricn

 

[Fallon]

OVRSZD - So I see rear implements with one side lower? Lots going on in the photo. Nice tractor BTW - Fallon- if adjustment is BS then my dealer is not very knowledgeable. Are you saying then the valve itself is defective? and the Kubota cylinders are crap to begin with? What do you mean by break float? getting in over my head with all this - maybe.

Ricn

Either stupid, blowing smoke or there is something really wired about those valves.

The cylinders that my dealer tried installing on my machine were not OEM Kubota. Some other 3rd party crap that was horribly designed (rod was 8" longer than the cylinder) and 2 of the 3 leaked bad. From what I can see all decent & many poor TnT cylinders take ages to get. Never actually seen an OEM Kubota TnT setup.

When you push your loader joystick all the way forward it goes into float. Where the hydraulics move freely & it won't exert any more pressure on the ground than the weight of the loader. Hydraulic fluid can move freely in & out of both ends of the cylinder. A check valve stops all fluid movement in & out of a cylinder unless the pressure on one port passes a certain high threshold. That stops float from working.

I'm a huge fan of float on my toplink. Whenever I'm mowing it's in float so the mower can get max articulation without binding because of the toplink. Also handy for letting impliments & the 3pt settle when trying to unhitch impliments.

 

[ovrszd]

So how long does it take to leak down and are you planning some sort of fix?

Ricn

It's my friend's tractor. One of a dozen he owns, and the smallest. He doesn't worry about it. Nature of the beast.

I just posted the pic to show that it's common. If it's something you can't accept then I suggest a Dual Pilot Control Valve which will lock the cylinder from drift in either direction. You will sacrifice the float function.

 

[Ricn]

Thanks for that info. If Kubota says they can't do anything well, I might go the control valve route. Tilt function is not something I have to use often, just that it came with the total package when ordering. We spend our money then expect things to work, don't we? Could also put the manual tilt system back on easily and just forget the cylinder altogether and the threaded tilt arm would work much better when using the mower; adjust it once and forget it.

Ricn

 

[ovrszd]

I have hydraulic tilt on my Kubota and use it a lot.

I have mechanical tilt on the Ford and rarely need more.

Just depends on your uses.

Yes, if I paid for it I expect it to function at the best possible level (pun intended).

 

[Ricn]

My intentions are, to give Kubota guys the best chance to make it work, after all, they sell this stuff all the time so hope it is just an irritation to them and something they see often enough to have some solution that makes it right. At least that is my goal at the moment. With others telling me here, there is no valve adjustment, this may not be fixable but could still be a bad cylinder or other? Does your Kubota leak down as well and if so, how quickly?

Ricn

Ricn

 

[ovrszd]

Yes, my Kubota leaks down. 15-20 minutes on the brush cutter before it's noticeable. My brush cutter is very, very heavy.

Against stiff opposition here on TBN I believe it's possible for a faulty cylinder to cause "some" drift. But sagging the length of the cylinder is valve problems, not cylinder problems.

Not trying to cast a dark shadow, just playing odds. Your dealer isn't going to be able to fix this problem without adding some sort of "locking" valve on the cylinder.

 

[Ricn]

Could be heading in that direction alright as several guys are saying "valves have no adjustment". What is disappointing; the total cost of dealing with Kubota and getting something like what I now have. I can live with a Lockout system if things end up there. Sometimes we learn to ask questions the hard way, this such a time.

Ricn

 

[Fallon]

My valves & TnT from FitRite took days to leak down on my old L3200. One of the junk TnT cylinders that didn't leak externally leaked down all the way in a few hours on my new L4060. Unplugged it & it didn't leak down at all. Do the problem is likely my valves. My dealer knows it is likely comming, once I get good TnT cylinders to test with. There is a spec for acceptable leak down rates my most valve manufacturers. It's typically a few teaspoons or tablespoons per hour. That generally translates to under an inch every couple hours on most cylinders.

The piloted check valve or some manual valve is a bandaid, but will fix it. **** no, no way, not an option on my new under warranty tractor. They will fix it (replace valves until they get one within leakdown spec in this case). But if it was an older machine I might consider piloted check valves rather than tear it apart to rebuild or replace valves.

 

[Ricn]

Fallon - I too feel as you do, no way on a new tractor. My TnT was added on six months after buying but all the parts are Kubota, or at least sold by Kubota. They are all dealer installed as well so as for a warrantee on all this, I just pray there is one! The dealer had no issues coming out and picking it up so maybe they will do something to help fix the issue. As with cars and trucks, warrantee is always a crap shoot!

Ricn

 

[Fallon]

I'm on good terms with my dealer. This was my 2nd machine from them in 3 years. They tried making the TnT right, but just had a crap supplier. They know the valve issue is likely going to be coming up & what the Kubota leakdown spec is that I will hold them to (if I can dig up that Email they got from corporate with the soec) But we agreed to table the issue until I had good TnT cylinders to test with.

 

[Ricn]

Yes, I too am on good terms with my dealer. So, after all this discussion and, going back to the dealer a couple times here are the results agreed to with my dealer early this morning:

Dealer has my tractor as stated looking at the valve situation including my flail mower. Their shop foreman verified there is no valve adjustment rather saying, the valves used in my TnT from Kubota will leak off above 800lbs weight but "having Zero bleed down with a 700lb mower hanging out there just is not going to happen". He also tested the bleed off time saying, the valve was in "speck" with the 700lb mower. He added that, when driving to and from fields or on roads with implement weight bouncing up and down can raise the pressure on the system beyond 800lbs causing bleed down to sometimes happen quicker. For now, I must believe him, not having spec sheets and all for these valves but also feel he is being honest with me AND, am not opposed to trusting folks until they prove otherwise..

Solution:
Dealer offered two fixes, either work for me:

1. remove the tilt cylinder and hoses plus replace the manual system along with some credit or cash return, whichever I want. This results in top cylinder being left in place but having original manual tilt adjustment when needed.

2. Install the lockout valve (Leonz suggestion) leaving the tilt cylinder in place then, when wanting to "tilt" just open and close the valve. He said Kubota factory does not recommend the lockout valve but he says there is nothing to damage by having one? I asked about my tractor warrantee et all, he responded nothing he would do will affect warrantee. I said go ahead and put in the "lockout" as I may want to use "tilt" at some time later.

So, thanks everyone for all the heads up, your knowledge and your suggestions. Have learned quite a bit about rear hydraulics and Flail Mowers both this past two weeks or so. Now, waiting my tractor coming home tomorrow and BTY- my dealer says "no charge" for anything including pickup and delivery of 25 miles each way...

Ricn